This application relates to methods of liberating and extracting intracellular material from plant, fungal, animal and bacterial cells.
Many plants, animals, bacteria, and fungi include useful material within their cells. These materials may be useful in pharmaceuticals, nutritional supplements, lotions, and the like. Others may have agricultural or industrial applications. For example, within the cells of the kava plant there are small granules of kava lactones, which are neurologically active. Pacific islanders cultivate the kava plant and make a sedative tea from chopped up pieces of kava roots, which has about 5-15% kava lactones by dry weight. A powder made from kava plants is sold in a capsule form as a nutritional supplement. However, because of the strength of the cellulose walls of the kava plants, it is difficult to extract the granules of kava lactones.
All plant and fungal cell walls are made primarily of cellulose, which is generally in the form of long, cross-linked strands. Such cell walls, which provide mechanical support for plants and fungi, are necessarily very sturdy and resistant to being easily opened or broken apart by mechanical or chemical means.
One method of breaking open the cell walls to release the material inside is by grinding or milling the plant or fungal material. However, many cell walls are only crushed by grinding or milling and are not substantially broken open. Much desirable material can remain within the shells of the crushed cell walls. Grinding or milling the plant or fungal material mixes together all material from the cells, including the cellulose, which makes it difficult to separate the useful material from unwanted debris. The ground or milled product is impurexe2x80x94the product retains all impurities that were in the stock material before grinding or milling. Because each plant sample may contain a different content of impurities or inactive ingredients, the efficacy of the ground or milled product for its intended purpose can vary widely.
Another method of opening cellulose cell walls to extract intracellular material is with chemicals that break down the cellulose walls. These chemicals may include solvents or acids, which may contaminate the desired material within the cells. Additional processing may be required to remove the chemicals, adding cost to the extraction process. The chemicals also may chemically alter the desired intracellular material, rendering it weakened, useless, or even harmful.
Some material from within cells may be extracted, as with the tea made from kava, by soaking the plant or fungal material in hot or boiling water. This process may leave much of the desired material within the cells. Subjecting the plant or fungal material to high temperatures may also break down the desired material, cause it to react with other material within the cells, or otherwise reduce its efficacy.
In one aspect, the invention provides a mechanical method of liberating an intracellular material from biological material having cells with cell walls. The method includes subjecting pieces of the biological material to rapidly alternating increasing and decreasing pressures, which may include shock waves, and opening the cell walls with the pressure increases and decreases. This liberates the intracellular material from the cells and produces a heterogenous mixture comprised of cell wall fragments and the intracellular material. It is believed that the rapidly alternating pressures causes the elastic limit of the intercellular bonds to be exceeded, breaking these bonds and separating cells from one another. The elastic limit of the cell walls is also exceeded, causing the cell walls to rend, tear, burst, or otherwise open and further fragment, thereby liberating the intracellular material. The method is particularly useful for liberating interacellular material from plant and fungal matter, which has cell walls formed primarily of cellulose.
In other features of this method, water and volatiles liberated from the cells with the pressure increases and decreases are vaporized such that the mixture has a lower water content and a lower volatile compound content than the biological material. The rapid pressure increases and decreases can also heat the biological material such that the mixture is produced with a temperature above an initial ambient temperature that depends upon the material and operating conditions.
A mill for subjecting the biological material to the pressure changes can include a housing characterized by a first end including an input adapted to introduce the biological material into the housing, a second end including an output adapted to remove the mixture, and longitudinally extending internal sides that form longitudinally extending interior corners where they meet. A rotor assembly within the housing is characterized by a rotatable shaft extending longitudinally through the housing between the first and second ends, and a plurality of rotors coupled to the shaft for rotation therewith. Rotors of the plurality of rotors each include a rotor plate having a peripheral edge forming a plurality of apices, and vanes on a side of the rotor plate which extend approximately radially from respective apices. An orifice plate is positioned between adjacently located pairs of the plurality of rotors. Each orifice plate extends inwardly from the internal sides of the housing to a central aperture which provides an orifice around the shaft. Each of the central apertures are smaller than rotor plates of the corresponding pair of rotors. Circumferentially spaced members, or posts, are located proximate each of the rotors. These members extend inwardly from the corners of the housing toward the rotors such that the vanes pass closely by the members as the rotor assembly rotates.
The biological material is fed into the input while the rotor assembly rotates, typically at speeds over about 2500 rpm, such that the biological material is entrained in a Coanda flow through the housing. Subjecting the biological material to the alternatingly increasing and decreasing pressure includes causing the bioloigical material to flow in an alternating outward and inward flow around peripheral edges of the rotor plates and through the orifices. The pressure on the biological material is alternately increased and decreased as the flow passes through each orifice and expands in the space below each orifice plate. Compression and decompression also occur in the flow as the vanes pass by flats and open corners of the housing sides and also as the vanes pass closely by the inwardly extending members. These compressions and decompressions may be of different magnitudes and durations. The Coanda flow is substantially without high angle impacts of the biological material on the rotor assembly, the orifice plates or the interior sides of the housing.
The rotors can be angularly offset from each other such that the compressions and decompressions are not synchronized. A series of compressions and decompressions is established at frequencies that depends on the number of rotors, the number of apices on each rotor, the number of sides in the housing, and the number of inwardly extending members. The pressure change frequencies can be tuned to resonate with a particular material and thereby more effectively disintegrate different materials. Hence, this type of mill may be referred to herein as a resonance disintegration (RD) mill.
According to another aspect of the invention, a method of liberating an intracellular resinous material from cells of bulk plant matter includes subjecting the bulk plant matter to rapid pressure increases and decreases, and opening walls of the cells with the pressure increases and decreases, thereby liberating the resinous material from the cells and producing a heterogenous mixture comprised of cell wall fragments and the resinous material. The method further includes placing particles of the mixture in a liquid, sedimenting particles of the resinous material in the liquid, and removing the sedimented particles of the resinous material.
The liquid may be water, an organic solvent, such as alcohol, or a mixture of water and the organic solvent. The particles placed in the liquid can be a screened fraction of the mixture. The method can also include drying the sedimented particles.
The plant matter can include pieces of Piper methysticum (kava), wherein the resinous material includes kava lactones.
According to yet another aspect of the invention, a method of liberating intracellular material from biological material having cell walls includes subjecting the biological material to rapid pressure increases and decreases, and exceeding the elastic limit of the cell walls with the rapid pressure increases and decreases. This thereby opens the cell walls and liberates the intracellular material. The method may further include the step of exceeding the elastic limit of intercellular bonds between the cells with the rapid pressure increases and decreases, thereby separating cells from each other.
The application of resonance disintegration to process biological materials, and in particular plant and fungal material, has several advantages over mechanical grinding or impact pulverization methods. An RD mill can be run at different speeds and can generate a wide range of different frequencies. Hence it is a versatile instrument for generating forces needed for RD. Heat generated during the rapid process of RD is modest and hence heat sensitive biological molecules are not destroyed. An RD mill can also accommodate materials that have significant water content. During milling, water is driven off resulting in a dry or dryer product.
The process product has a reduced water content. When plant or fungal material is processed, cellulose particles in the product have a generally larger size than other product materials. These properties each make the desired material easier to separate from the cellulose, for example, with an air classifier or by screening. A purer and more efficacious product is produced.
When the water content of the biological material is about 40% by weight or less, the liberated intracellular materials are in the form of a dry powder, which is easy to assimilate by ingestion. The process increases the available exposed surface of the intracellular material for more efficient extraction with aqueous or organic solvents.
The liberating process can be carried out without the use of chemicals or solvents, thereby making a more pure product and reducing the risk of chemically altering the product. Bulk materials, including pieces of plant fungal and animal matter, can be processed with an RD mill. More pure and more concentrated product of intracellular material can be produced according to these methods in a cost effective manner.
An added benefit of using an RD mill to liberate intracellular products from biological material is that it can destroy bacteria, thereby reducing the bacterial load of the processed material.